Isaiah 21: 3-5 “Therefore are my loins filled with pain: Pangs have taken hold upon me, as the pangs of a woman that travaileth: I was bowed down at the hearing of it: I was dismayed at the seeing of it. My heart panted, fearfulness affrighted me: the night of my pleasure hath He turned into fear unto me. Prepare the table, watch in the watchtower, eat, drink, arise, ye princes, and anoint the shield.”
Isaiah, as he saw the vision of the coming destruction, was so horrified that he doubled over in pain; the pain is described as being the like that of a woman in labor. The vision must have seemed to him as if he were actually there, as he mentions both hearing and seeing.
His heart panted; the meaning here is similar to staggering, going astray.
The night of his pleasure doubtless refers to the drunken feast of Belshazzar in Daniel 5. There were watchmen placed in the towers, and it seems they, too, were eating and drinking in complete security until they realized that security had been breached, and they were called upon to fight.
Anoint the shield: The shields used in warfare consisted of several layers of thick leather stretched over a metal frame. Often there were pieces of bone or metal embedded in the leather. The whole shield was regularly rubbed with oil to keep the leather from cracking, and the metal from rusting.
Isaiah watched all this happen as if he were actually there. First the revelry, then suddenly the shouts, screams, and clangor of battle. What a sight it must have been as the comfort of the Babylonians was quite suddenly destroyed by the enemy that had found a way inside the city. You can read more about it In Jeremiah 51:11 and Daniel 5.